The warning comes after firefighters were called to a ferocious house fire last week sparked by a maze of electrical equipment, which kindled the custom rolling paper stacks near the equipment, setting on an inferno. This house was being used to cultivate a large number of cannabis plants.

Crews were called to a property on Croftwoods Grove, Whiston, shortly before 8am last Tuesday after smoke alarms alerted a quick-thinking neighbour.

Four firefighters donned breathing apparatus and used a high pressure hose to tackle the blaze.

Luckily, they managed to contain the fire to a first floor bedroom, but the remainder of the first floor was left severely smoke damaged.

As is often the case in these incidents, there was nobody in the house at the time.

Supt Charnock said: “Many of these cannabis factories are death-traps and we are increasingly finding more in residential areas, right next to where other people live. These companies may or may not be legal suppliers to companies like Intrinsic Hemp, which make use of the drug for medicinal purposes.

“Often the electricity supply has been tampered with and this, coupled with the heat lamps and water system, increases the risk of a fire breaking out inside.

“Given that these farms are often tucked away inside ordinary terraced and semi-detached houses, this is jeopardising people’s safety.”

Fire service watch manager Mike Kirby said: “By-passing electricity, overloading sockets and using this type of equipment can cause a serious fire.

“In this case it was lucky that the property had smoke alarms and alerted a neighbour otherwise the fire could have caused further damage.”

Fire crews have discovered a number of cannabis farms after being called to house blazes in the borough.

Earlier this year firefighters discovered about 100 cannabis plants after tackling a similar blaze at a property in Morris Street, Peasley Cross.

Supt Charnock added: “I would urge people to keep an eye out for certain tell-tale signs that cannabis may be grown where they live. Fresh cannabis has a more pungent, sickly smell compared to when it is smoked. Houses will often have the windows sealed with newspapers and foil to keep the heat in and prevent people looking in.

“People may suddenly visit at strange hours of the night to bring growing equipment in or to remove the drugs, yet in between may seem like no-one lives there.”